SEMICONDUCTOR DEVICE WITH METAL GATE AND HIGH-K MATERIALS AND METHOD FOR FABRICATING THE SAME

摘要

A semiconductor device includes a substrate including first and second regions. A first gate stack structure containing a first effective work function adjust species is formed over the first region and a second gate stack structure containing a second effective work function adjust species is formed over the second region. A channel region is formed under the first gate stack structure and contains a threshold voltage adjust species.